Change of sub-brokership from one member to another member ?

Change of sub-brokership from one member to another member ?

Can anyone tell that :--

a) what is the procedure of changing of sub-brokership from present main broker to some other main broker ?

b) How much time it takes to change / switch.

c) What to do if present main broker is not issuing NOC.

d) Is there any charges involved if a sub-broker surrender his sub-brokership with present broker ? can present broker debit any charges from sub-broker for surrendering the CTCL ID's ?

If anyone have experience with above topic then pls. reply